Stock developer solutions for photoresists contain an organic base free from metal ions and at least one compound having a specified weight average molecular weight that is selected from among polyethylene oxide compounds, polypropylene oxide compounds and ethylene oxide/propylene oxide adducts. The stock developer solutions may be diluted to requisite concentrations to prepare developer solutions for photoresists. By adding one or more of the specified compounds to the organic base free from metal ions, one can produce highly compatible stock developer solutions for photoresists that are concentrated, that have high stability in quality and that permit ease in handling and quality control. The stock developer solutions may be diluted to prepare developer solutions that are small in the tendency to foam and effective in defoaming, that assure uniform wetting and that are capable of forming resist patterns faithful to mask patterns.